The design and manufacturing cost of aluminum profile extrusion molds accounts for about 20% of the total production cost. It is one of the key technologies in the aluminum profile extrusion industry, which has many variables and develops rapidly. It involves many aspects, including material selection, design, manufacturing, inspection, mold repair, and management, and is also one of the areas with considerable development potential.
1. Strictly implement the production process rules and regulations for aluminum profiles
It is essential to strictly follow the corresponding aluminum profile extrusion process. During the machine start-up, the temperature of the middle section of the aluminum billet furnace should be set at 530-550℃, and the outlet section should be set at 480-500℃. The insulation time must be sufficient to ensure that the aluminum billet is evenly heated throughout (both the core and the surface). This prevents inconsistent temperatures inside and outside the billet (insufficient core temperature), which can increase elastic deformation of the die, aggravate issues such as 'uneven wall thickness' and 'inconsistent lengths,' and even lead to plastic deformation of the extrusion die, rendering it scrap.
2. Ensure the 'three hearts in one'
The centers of the extrusion barrel, the extrusion rod, and the die base must be visually concentric. No obvious eccentricity is allowed, otherwise it will affect the flow rate at various parts of the product, and may even impact the formation of the product or cause the lengths of the two sides of the extruded product to differ significantly, making extrusion production impossible. For multi-hole molds with more than two outputs, the requirements are even stricter.
3. Properly select support pads
It is necessary to choose appropriately sized double-hole, large cantilever specialized support pads to reduce the elastic deformation of the lower mold, ensuring stable extrusion product forming with minimal dimensional variation. Moreover, the specialized double-hole support pads must be prepared in advance before the mold is taken out of the furnace, to avoid excessive cooling of the mold due to the time spent searching for support pads, which could lead to defects. It is also recommended that the support pads be heated, generally controlling the temperature between 350 and 450℃. This is especially important for irregular complex cross-sections and multi-hole series, where it is essential to select suitable specialized support pads.
4. Strengthen information feedback during the aluminum profile extrusion process
1) Feedback on Extrusion Die Clogging
There are many reasons for die clogging, such as mold processing issues, material getting stuck in empty cavities, burrs from empty cavity processing, small empty cavities, unreasonable empty cavity depths, and other influencing factors. Additionally, unreasonable mold design work, such as incorrectly designed flow guides or distribution holes, can also easily lead to die clogging. Generally, people who have not received specialized training may find it difficult to explain this clearly. It is best for trained mold repair personnel to inspect the mold in person, identify the cause, perform mold conditioning, repair the mold, and propose modification plans.
2) Feedback on Extrusion Product Formation
Besides clearly marking the extrusion die number on the billet, it is also necessary to mark the overall flow direction on the billet, which may be difficult to see. For example, "converging extrusion" indicates that in the actual extrusion process, the inner side of the two holes is slower and the outer side faster; "diverging extrusion" indicates that the inner side of the two holes is faster and the outer side slower; "left long, right short" means the left branch is long and the right branch is short. The difference in length should also be specified. Because the distance from the saw cut to the extrusion die outlet is approximately 6 meters, it is usually represented as "A meters / 6 meters," meaning the difference in length is A meters per 6 meters. Such complete and accurate expression helps mold repair personnel make correct judgments and repairs.
3) Feedback on Dimensional Deviations
When the extrusion product forms normally but dimensional deviations occur, it is essential to take a sample segment and make complete and accurate markings (extrusion die number, extrusion direction, dimensional defects, etc.). Any incorrect marking may lead to repairing the wrong mold, so extreme caution is required. Providing accurate material samples is best done including sections from the beginning, middle, and end of the billet.
